In an image forming apparatus, such as a copy machine or a printer, toner is scattered in the apparatus from a developing unit of an image forming section which is included in the image forming apparatus. The scattered toner is attached to a gear or the like, and becomes a cause of failure. In order to reduce the scattered toner, it is necessary to take measures to provide a duct for withdrawing the scattered toner, a filter and a fan which are provided in the duct. However, in a case in which components, such as the duct, the filter, and the fan, are provided, there is a possibility that a size of the apparatus increases.